1. Field of the Invention
The present invention relates to a method of and a system for cleaning articles to remove foreign matters, such as impurities, dust or the like from surfaces of the articles.
2. Description of the Prior Art
The technique disclosed in Japanese Patent Laying-Open No. 45575/72 laid open for public inspection on Dec. 25, 1972 is arranged such that a plurality of treatment baths receiving therein respective cleaning liquids are provided; a cartridge is provided for holding therein a plurality of articles to be cleaned; the cartridge having held therein the articles is immersed in a first of the cleaning liquids filled in a first of the treatment baths to clean the articles by the first cleaning liquid; after the articles are cleaned by the first cleaning liquid within the first treatment bath, the cartridge having held therein the articles is moved out of the first treatment bath through the free surface of the first cleaning liquid within the first treatment bath to expose the articles held in the cartridge to an environmental atmosphere; the cartridge having held therein the articles is then introduced from the environmental atmosphere into a second of the treatment baths through the free surface of a second of the cleaning liquids filled therein and immersed in the second cleaning liquid to clean the articles by the second cleaning liquid; after the articles are cleaned by the second cleaning liquid within the second treatment bath, the cartridge having held therein the articles is moved out of the second treatment bath through the free surface of the second cleaning liquid therewithin the expose the articles held in the cartridge to the environmental atmosphere; and so on.
A major portion of foreign matters removed from the surfaces of the articles by the cleaning operation within each treatment bath is floated on the free surface of the cleaning liquid within the treatment bath, and the remaining minor portion of the foreign matters is suspended in the cleaning liquid. It is of course that the foreign matters are suspended in the environmental atmosphere. When the articles to be cleaned are into contact with any solid body, the foreign matters deposited on the solid body are transferred to the articles.
As described previously, the technique disclosed in the Japanese patent laying-open publication is arranged such that the cartridge having held therein the articles to be cleaned is moved out of each treatment bath through the free surface of the cleaning liquid therewithin into the environmental atmosphere, after the cleaning of the articles by the cleaning liquid within the treatment bath, and is then moved from the environmental atmosphere into the adjacent treatment bath through the free surface of the cleaning liquid therewithin. This causes the foreign matters floated on the free surface of the cleaning liquid to be deposited on the articles, and also causes the foreign matters suspended in the environmental atmosphere to be deposited on the articles. Thus, the articles are again contaminated with the foreign matters after each cleaning operation, and it is difficult to expect to have a high cleaning efficiency.